1. Field of the Invention
The present invention relates to rhinitis treatment regimens, more particularly, to prepackaged therapeutic regimens for the symptomatic treatment of rhinitis which combine decongestant and antihistamine medications in a manner so as to avoid sedation when sedation is undesired and to avoid stimulation when stimulation is undesired.
2. The Prior Art
Rhinitis refers to an inflammatory disorder of the nasal passages. The symptoms of rhinitis typically consist of sneezing, rhinorrhea, nasal congestion, and increased nasal secretions. Failure of treatment of rhinitis may lead to other disorders including infection of the sinuses, ears and lower respiratory tract.
Two types of oral medication are commonly used to treat rhinitis: decongestants and antihistamines. Decongestants and antihistamines differ in mechanism of action, therapeutic effects, and side effects. It is common practice to combine the use of these two to bring about more complete symptom relief of rhinitis than with either entity alone.
Decongestants commonly used to treat rhinitis include the adrenaline-like agents pseudoephedrine and phenylpropanolamine. These agents act to constrict vessels in the nasal mucus membranes and thereby decrease tissue swelling and nasal congestion. Decongestants are found to be better than antihistamines for restoring the patency of congested nasal airways. Like adrenaline, nasal decongestants are stimulatory and produce side effects which may be tolerated during the day, and even be considered desirable to counter fatigue which is known to accompany other symptoms of rhinitis. Decongestants, however, may produce nervousness, restlessness, and insomnia if taken at night. This can be a source of confusion for individuals who mistakenly attribute their inability to sleep to the malaise accompanying rhinitis rather than to the decongestant medication.
Histamine is a mediator released from cells which line the walls of the nasal mucous membranes (mast cells). When released, histamine is known to bind to local receptors and thereby cause sneezing, nasal itching, swelling of the nasal membranes, and increased nasal secretions. Antihistamines relieve these effects, albeit by a different mechanism than decongestants. Antihistamines block the binding of histamine to histamine receptors in the nasal membranes. Antihistamines preemptively bind to histamine receptors and are effective only if given prior to histamine release (once histamine is released and binds to the receptor, it is too late). Although individuals typically take antihistamines after symptoms occur, it is more desirable to dose antihistamine so as to effect therapeutic activity in anticipation of the peak times of histamine release. Individuals with rhinitis commonly experience peak symptoms in the morning hours on awakening, a time concomitant with peak histamine release and coinciding with peak exposure to airborne allergens which stimulate histamine release in sensitive individuals.
To improve upon the sedation of such older antihistamines, newer antihistamines with little or no sedation have more recently been developed.
The combining of decongestants and antihistamines utilizes two mechanistic approaches, and has been shown to offer more complete relief of rhinitis symptoms than therapy with either component alone. Consequently, many products have been formulated so that their dosage units contain both. While individuals are known to vary in their susceptibility to side effects, the incorporation of decongestant and sedating antihistamine into a single dosage unit represents an attempt to balance stimulation and sedation of the components. Consequently, some individuals experience irritability and/or sedation with these combinations. Examples of commercial formulations containing decongestant and sedating antihistamine include:
1. CHLOR-TRIMETON.RTM. 4 hour Allergy/Decongestant which contains 4 mg of chlorpheniramine (sedating antihistamine) and 60 mg pseudoephedrine sulfate (stimulating decongestant), and which is recommended to be taken every 4 to 6 hours (1/2 this dosage for children 6 to under 12);
2. CHLOR-TRIMETON.RTM. 12 hour Allergy/Decongestant which contains 8 mg of chlorpheniramine (sedating antihistamine) and 120 mg pseudoephedrine sulfate (stimulating decongestant), and which is recommended to be taken every 12 hours (adults and children over 12 years of age only);
3. BROMFED.RTM. Tablets which contains 4 mg of brompheniramine (sedating antihistamine) and 60 mg pseudoephedrine sulfate (stimulating decongestant), and which is recommended to be taken every 4 to 6 hours (1/2 this dosage for children 6 to under 12);
4. BROMFED.RTM. Capsules which contains 12 mg of brompheniramine (sedating antihistamine) and 120 mg pseudoephedrine sulfate (stimulating decongestant), and which is recommended to be taken every 12 hours (adults and children over 12 years of age only);
5. BENADRYL.RTM. Allergy Decongestant Tablets which contains 25 mg of diphenhydramine hydrochloride (sedating antihistamine) and 60 mg pseudoephedrine sulfate (stimulating decongestant), and which is recommended to be taken by adults and children over 12 years of age every 4 to 6 hours, not to exceed 4 tablets in 24 hours; and
6. TAVIST-D.RTM. Tablets which contains 1.34 mg clemastine fumarate (sedating antihistamine) and 75 mg phenylpropanolamine hydrochloride (stimulating decongestant), and which is recommended to be taken every 12 hours (adults and children over 12 years of age only).
More recently, formulations have been commercialized which incorporate both a decongestant and a non-sedating antihistamine into a single dosage unit. While such formulations offer the advantage in being non-sedating, such combinations might be expected to provoke a greater incidence of nighttime irritability and insomnia because the stimulating side effects of the decongestant are not attenuated by concomitant use of sedating antihistamine. Indeed, a 25% incidence of insomnia has been disclosed among users of the combination of non-sedating antihistamine terfenadine and pseudoephedrine. Examples of such formulations include:
1. SELDANE-D.RTM. Extended-Release Tablets which contains 60 mg terfenadine (non-sedating antihistamine) and 120 mg pseudoephedrine hydrochloride (stimulating decongestant), and which is recommended to be taken every 12 hours (adults and children over 12 years of age);
2. CLARITIN-D.RTM. 24 HOUR Extended-Release Tablets which contains 10 mg loratidine (antihistamine) and 240 mg pseudoephedrine hydrochloride (decongestant) and, which is recommended to be taken every 24 hours (adults and children over 12 years of age); and
3. ALLEGRA-D.TM. which contains 60 mg fexofenadine (non-sedating antihistamine) and 120 mg pseudoephedrine hydrochloride (stimulating decongestant), and which is recommended to be taken every 12 hours (adults and children over 12 years of age).
U.S. Pat. No. 4,295,567, issued to Knudsen, teaches a regimen to avoid sedation from antihistamines when sedation is undesired. The Knudsen patent therefore does not apply to antihistamines which are not sedating. In accordance with Knudsen, prepackaged regimens for treating the symptoms of rhinitis have been commercialized, and employ decongestant for daytime and decongestant plus sedating antihistamine for night. Examples in accordance with Knudsen include:
1. DAYTIME & NIGHTTIME ACTIFED ALLERGY.RTM. which contains 30 mg pseudoephedrine (decongestant) in the daytime formulation, and 30 mg pseudoephedrine (decongestant) and 25 mg diphenhydramine (antihistamine) in the nighttime formulation; and
2. CONTAC DAY & NIGHT ALLERGY/SINUS.RTM. which contains 60 mg pseudoephedrine (decongestant) and 650 mg acetaminophen (analgesic) in the daytime formulation, and 60 mg pseudoephedrine (decongestant), 50 mg diphenhydramine (antihistamine), and 650 mg acetaminophen (analgesic) in the nighttime formulation.
Regimens have also been commercialized which incorporate a decongestant for daytime and not for nighttime. An example of one such prepackaged regimen is SYN-RX.TM., which contains 60 mg pseudoephedrine HCL and 600 mg Guaifenesin in the day formulation, and 600 mg Guaifenesin in the nighttime formulation. These regimens avoid stimulation from decongestant at night, however lack antihistamine. Further, they neither contain medication which would be effective for rhinitis symptoms at night, nor anticipate peak symptoms of rhinitis in the morning hours on awakening.
While the problem of sedation with combined decongestant and sedating antihistamine treatment is addressed by Knudsen, the problem of nighttime irritability and insomnia is not. Indeed, all commercialized decongestant and antihistamine regimens according to Knudsen have the potential to cause irritability and insomnia at night.
Similarly, while the problem of sedation with combined decongestant and sedating antihistamine treatment are addressed in single entity combinations which employ decongestants and non-sedating antihistamines, the problem of nighttime irritability and insomnia is not. Formulations which incorporate decongestant and non-sedating antihistamine into a single dosage unit are yet more likely to produce irritability and insomnia at night than formulations with sedating antihistamine.
It is well known that individuals with rhinitis utilize antihistamines and decongestants hundreds of millions of times a year. It is not uncommon for inappropriate choices to result in symptomatic worsening rather than improvement. Individuals often use sedating medication unknowingly or inappropriately. Decongestants taken at night not only produce insomnia in a sizable portion of users, but also daytime irritability, fatigue, and malaise from lack of rest. Users are known to mistakenly ascribe such symptoms to rhinitis rather than to medication. Professional as well as consumer confusion is widely encountered with these medications and unnecessarily negative consequences occur both by self-selection and prescription. There is a present need for preformulated regimens which advantageously use antihistamines and decongestants for rhinitis in a manner to circumvent this confusion, and to avoid both daytime sedation and nighttime stimulation.
Adherence to medication therapy and prevention of medication error are considerable medical problems and are improved with measures to establish simplicity, reduce confusion, and increase convenience. The proposed use of a multiplicity of dosage units as a regimen may be associated with dosage units being confused with each other, inadvertently switched, lost, misplaced, or ignored. Another problem associated with treatment using a plurality of dosage units is the lack of indicia which distinguish the dosage units from each other and signify and verify their use together and readily available instructions for coordinating the medications. Individuals are known to lose instructions issued separate from the medication. Haphazard selection and organization of medications can result in treatment failure and in the patient's requiring additional medical attention involving time, expense, and personnel costs and effort to instruct and organize therapy. Cost factors and outcomes are being carefully considered in the current medical climate. Improvements in organization and teaching including devices and methods which would help patients be more cognizant of their proper therapeutic requirements are considered desirable in view of limitations in time and costs for medical personnel. Successful therapy for rhinitis is less costly than unsuccessful treatment which eventuates in complications or multiple clinic visits.